160883-09-0Relevant articles and documents
The first Cu(I)-mediated nucleophilic trifluoromethylation reactions using (trifluoromethyl)trimethylsilane in ionic liquids
Kim, Jinwi,Shreeve, Jean'ne M.
, p. 2728 - 2734 (2007/10/03)
The new ionic liquids (5a-8a) were used as reaction media for nucleophilic trifluoromethylation reactions of trifluoromethyl(trimethyl)silane with (1) aryl, allyl, benzyl, and alkyl halides in Cu(I)-mediated C-C bond formation reactions, and (2) carbonyl functionalities catalyzed with Ph3P or CsF. In addition, conversion of benzyl bromide as a model compound to benzyl fluoride was examined in 6a using CsF as the fluorinating reagent. The morpholiniumbased ionic liquid (6a) stood out as an efficient solvent system comparable to organic solvents and superior to the other new ionic liquids prepared in this work as well as to [bmim]+[PF6]-. Neat reactions of N-methyloxazolidine (1), Af-methylmorpholine (2), A'-methylimidazole (3) or TV-methyltriazole (4) with 2-(2-ethoxyethoxy)ethyl bromide (BrCH2CH2OCH2CH2OCH 2CH3, 9) or 2-bromoethyl methyl ether (BrCH 2CH2OCH3,10) at 75 or 105 °C gave the A'-(2-ethoxyethoxy)ethyl- or N-methoxyethyl-substituted oxazolidinium, morpholinium, imidazolium and triazolium quaternary bromides (1a-4a, 1b-4b) which were metathesized with LiN(SO2CF3)2 to form the respective roomtemperature liquid bis(trifluoromethanesulfonyl)amides 5a-8a and 5b-8b in high yields with transition or melting points 310 °C as determined by thermogravimetric analyses (TGA). Densities range between 1.29 and 1.53 g cm-3 at 25 °C.
Synthesis and Solvolysis of 7-(Perfluoroalkyl)-7-bicycloheptyl Derivatives
Nelson, Derek W.,O'Reilly, Neil J.,Speier, Jon,Gassman, Paul G.
, p. 8157 - 8171 (2007/10/02)
Several α-(trifluoromethyl)- and α-(pentafluoroethyl)carbinols were synthesized by the addition of perfluoroalkylating agent (TMSCF3, TMSC2F5, and/or C2F5Li) to polycyclic ketones.An improved procedure for the preparation of α-(perfluoroalkyl)trimethylsilyl ethers from (perfluoroalkyl)trimethylsilanes and ketones was developed to facilitate the synthesis of the compounds of interest.All of the alcohols featured the bicycloheptyl skeleton or some analog of this structure containing double bonds or cyclopropyl groups.Sulfonate esters of the carbinols were prepared, and these sulfonates were solvolyzed in different solvents to examine the competition between destabilization of the carbocationic intermediates by perfluoroalkyl groups and stabilization by neighboring-group participation.The extent of the destabilization of the cations was gauged by the difference in rates of solvolysis of the α-hydrogen and α-(perfluoroalkyl) derivatives.The kα-H/kα-RF ratios ranged from 8 to ca. 1E4, and the extent of anchimeric assistance that occurred in each system influenced the difference in rates.The pentafluoroethyl group exerted a slightly smaller rate-retarding effect when compared to the trifluoromethyl group (kα-C2F5/kα-CF3 = 1.1-8.0).The products of the solvolysis reactions revealed a general trend of destabilization of both localized and delocalized cations by perfluoroalkyl groups.
